| Table 8-2 Immunohistochemical Stains |
| Marker | | Normal Location in | | Positive in |
| Epithelial markers |
| | Cytokeratin (Keratin) | | Epithelial cells, ± sweat glands | | Epithelial tumors, some adnexal tumors |
| | | | | | | | | | | | | | | | | | | Types of keratin:
AE1 (low molecular weight): basal epidermis, sweat glands
AE3 (high molecular weight): mid to superficial epidermis
CAM 5.2: Paget’s disease; CK 7: Paget’s disease; CK 20: Merkel cell carcinoma | | | | | | | | | | | | | | |
|
| Melanocytic |
| | S100 | | Melanocytes, neural cells, smooth/skeletal muscle cells, Langerhans cells, eccrine and apocrine glands, chondrocytes | | Langerhans cell histiocytosis, melanoma, granular cell tumor, eccrine neoplasms, neural tumors, liposarcoma |
| | HMB-45 | | Melanocytes (less sensitive but more specific than S100) | | Melanoma, some normal nevi, Spitz nevus, angiomyolipoma, breast carcinoma |
| | Of note, MART-1/Melan A and Mel-5 are comparable to HMB-45 |
| Adnexal |
| | CEA (Carcinoembryonic antigen) | | Eccrine glands | | Paget’s disease, extramammary Paget’s, epithelioid sarcoma (sometimes), sweat gland tumors, adenocarcinomas (gastric, lung, breast, etc.) |
| | EMA (Epithelial membrane antigen) | | Eccrine glands, some epithelial malignancies | | Paget’s disease, merkel cell carcinoma, meningioma, epithelioid sarcoma, most epithelial tumors |
| Muscle |
| | Desmin | | Muscle cells
(skeletal and smooth muscle) | | Leiomyoma, leiomyosarcoma, glomus cell tumor (focally +), embryonal rhabdomyosarcoma |
| | Vimentin | | Muscle cells, fibroblasts, endothelial cells, histiocytes, lymphocytes, Schwann cells, melanocytes | | Mesenchymal tumors (sarcomas, lymphomas, atypical fibroxanthoma, dermatofibrosarcoma protuberans), melanoma, glomus cell tumor |
| | Smooth muscle actin | | Myofibroblasts, muscle cells | | Glomus tumors, smooth muscle tumors, some atypical fibroxanthomas |
| Neural |
| | Neuron-specific enolase (NSE) | | Nonspecific neuroendocrine marker | | Granular cell tumor, merkel cell carcinoma, other neuroendocrine tumors, some melanocytic tumors (melanoma), schwannoma |
| | Glial fibrillary acidic protein (GFAP) | | Glial cells, astrocytes, Schwann cells | | Nerve sheath tumors |
| | Chromogranin | | Neuroendocrine neoplasms | | Merkel cell carcinoma |
| | Synaptophysin | | Neuroendocrine neoplasms | | Merkel cell carcinoma |
| | Myelin basic protein
(MBP) | | Myelin sheath tissue, Schwann cells | | Neurofibroma, neuroma, granular cell tumor |
| Endothelial |
| | Factor VIII–related antigen (von Willebrand) | | Endothelial cells
(not as sensitive as CD31) | | Vascular tumors (both benign and malignant) |
| | CD31 | | Monocytes, granulocytes, T/B cells, endothelial cells | | Vascular neoplasms (angiosarcoma) |
| | Ulex europaeus agglutinin 1 (UEA) | | Endothelial cells, most eccrine glands, keratinocytes | | Vascular tumors |
| | CD34 | | Endothelial cells, nerves, hematopoietic cells | | Vascular tumors (benign/malignant), dermatofibrosarcoma protuberans, vascular tumors (not as sensitive as ulex), neurofibroma, epithelioid sarcoma, spindle cell lipoma, fibrous papule |
| Miscellaneous |
| | Factor XIIIa | | Macrophages, dermal dendrocytes, platelets | | Dermatofibroma, xanthoma disseminatum, fibrous papule, AFX, xanthogranuloma |
| | Bcl-2 | | Indicator of ↓ apoptosis, ↑ cell longevity | | Follicular center cell lymphoma |
| | Gross Cystic Disease Fluid Protein 15 (GCDFP-15) | | Apocrine glands | | Apocrine tumors, breast carcinoma, salivary gland tumors |
| | | | | | |
